Conservation genetics of the endangered Spotted Turtle (Clemmys guttata) illustrate the risks of “bottleneck tests”

Canadian Journal of Zoology, Volume 0, Issue 0, Page 149-162, e-First articles.

Studies of population genetics in turtles have suggested that turtles do not experience genetic impacts of bottlenecks as strongly as expected. However, recent studies cast doubt on two commonly used tests implemented in the program BOTTLENECK, suggesting that these findings should be re-evaluated. The Spotted Turtle (Clemmys guttata (Schneider, 1792)) is endangered both globally and within Canada, but genetic data required to develop effective recovery strategies are unavailable. Here, we conducted the first study of population genetic structure in C. guttata. We then used multiple small populations of C. guttata as replicates to test whether the commonly used program BOTTLENECK could detect the genetic signature of bottlenecks in our study populations, which are all thought to have experienced significant declines in the past 2–3 generations (75 years). Turtles (n = 256) were genotyped at 11 microsatellite loci. A suite of Bayesian population genetics analyses and a principal coordinates analysis identified a minimum of 6 distinct genetic populations and a maximum of 10 differentiated subpopulations across the sampled Canadian range of C. guttata, which corresponded to demographically independent units. BOTTLENECK failed to detect population declines. A literature review found that bottleneck tests in 17 of 18 previous genetic studies of tortoises and freshwater turtles were based on sub...

Source: Canadian Journal of Zoology - January 31, 2014 Category: Zoology Tags: article Source Type: research